Autoxidation of Azulene in Aprotic Polar Solvents

Abstract

Autoxidation of azulene [1 A] at 110°C in HMPA (or DMF) yielded sixteen separable products, including three new compounds ([1 D₁], [1 E₁], and [1 G₂]). These products were monomeric, dimeric, and trimeric products containing an extranuclear carbon unit ([1 F], [1 G₁], [1 C], [1 G₂] and [1 D₁]), naphthoquinones ([1 E₄], [1 H₁], and [1 H₂]), benzenoids ([1 E₂], [1 I₁], [1 E₃], and [1 I₂]), biazulene [1 B], dimeric products with rearra ngement ([1 E₁] and [1 D₂]), and substituted azulene by the reaction with solvent [1 H₃]. The structures of these compounds were established on the basis of the spectroscopic data (UV, MS, IR, and NMR).